Saint Petersburg's 2025 population is now estimated at 5,597,340. In 1950, the population of Saint Petersburg was 2,902,790. Saint Petersburg has grown by 15,630 in the last year, which represents a 0.28% annual change.These population estimates and projections come from the latest revision of the UN World Urbanization Prospects. These estimates represent the Urban agglomeration of Saint Petersburg, which typically includes Saint Petersburg's population in addition to adjacent suburban areas.